OXIDATIVE DEHYDROGENATION OF ISOBUTANE ON NICKEL AND CHROMIUM-OXIDE SYSTEMS DISPERSED ON DIFFERENT SUPPORTS

Nickel oxide and chromia supported on ThO2, CeO2, MgO and SiO2 have be en tested in oxidative dehydrogenation of isobutane. Both NiO- and Cr2 O3-based systems have been found active in this reaction already aroun d 300 degrees C, the catalytic performance being dependent on the natu re of the support. Chromia-based catalysts are more active and selecti ve as compared with the NiO-based ones. The highest activity and selec tivity have been observed for the CrOx/CeO2 system. The basicity of th e catalysts determined by a probe reaction of the isopropanol dehydrog enation follows the same sequence as the total activity in the oxidati ve dehydrogenation of isobutane, which suggests an activation of the C -H bond on basic centres of the catalysts.